Fiorella Guadagni

Genetics of ischemic stroke, stroke-related risk factors, stroke precursors and treatments

Stroke remains a leading cause of death worldwide and the first cause of disability in the western world. Ischemic stroke (IS) accounts for almost 80% of the total cases of strokes and is a complex and multifactorial disease caused by the combination of vascular risk factors, environment and genetic factors. Investigations of the genetics of atherosclerosis and IS has greatly enhanced our knowledge of this complex multifactorial disease. In this article we sought to review common single-gene disorders relevant to IS, summarize candidate gene and genome-wide studies aimed at discovering genetic stroke risk factors and subclinical phenotypes, and to briefly discuss pharmacogenetics related to stroke treatments. Genetics of IS is, in fact, one of the most promising research frontiers and genetic testing may be helpful for novel drug discoveries as well as for appropriate drug and dose selection for treatment of patients with cerebrovascular disease.

Standard preanalytical coding for biospecimens: review and implementation of the Sample PREanalytical Code (SPREC).

The first version of the Standard PREanalytical Code (SPREC) was developed in 2009 by the International Society for Biological and Environmental Repositories (ISBER) Biospecimen Science Working Group to facilitate documentation and communication of the most important preanalytical quality parameters of different types of biospecimens used for research. This same Working Group has now updated the SPREC to version 2.0, presented here, so that it contains more options to allow for recent technological developments. Existing elements have been fine tuned. An interface to the Biospecimen Reporting for Improved Study Quality (BRISQ) has been defined, and informatics solutions for SPREC implementation have been developed. A glossary with SPREC-related definitions has also been added.

Identification of evidence-based biospecimen quality-control tools: a report of the International Society for Biological and Environmental Repositories (ISBER) Biospecimen Science Working Group.

Control of biospecimen quality that is linked to processing is one of the goals of biospecimen science. Consensus is lacking, however, regarding optimal sample quality-control (QC) tools (ie, markers and assays). The aim of this review was to identify QC tools, both for fluid and solid-tissue samples, based on a comprehensive and critical literature review. The most readily applicable tools are those with a known threshold for the preanalytical variation and a known reference range for the QC analyte. Only a few meaningful markers were identified that meet these criteria, such as CD40L for assessing serum exposure at high temperatures and VEGF for assessing serum freeze-thawing. To fully assess biospecimen quality, multiple QC markers are needed. Here we present the most promising biospecimen QC tools that were identified.

Quantitative analysis of CEA expression in colorectal adenocarcinoma and serum: Lack of correlation

Tissues and sera from 110 patients diagnosed with colorectal primary carcinoma, 20 patients with benign colorectal diseases and 31 healthy donors were subjected to quantitative CEA analysis. Multiple samples from tumor lesions and autologous histologically normal mucosa (10 cm from the tumor) were obtained at the time of surgery (cancer patients) or endoscopy (benign patients and healthy volunteers). CEA content was measured in protein extracts obtained from these tissues using a quantitative RIA method. A limit of normality for CEA content was established as 300 ng/mg of protein. When this was taken as cut‐off, 104 of 110 (94.5%) tumor lesions and 51 of 110 (46.4%) autologous histologically normal colonic mucosa from cancer patients had elevated CEA levels. No correlation with stage of disease was found, while a correlation was observed with degree of tumor differentiation. A statistically significant difference between CEA content in tumor lesions and in histologically normal mucosa from cancer patients was observed (p = −0.001). Moreover, CEA content was statistically higher in the normal mucosa from cancer patients than in that from healthy donors (p = 0.005). CEA content in tissue specimens from benign lesions differed significantly from that in tissue from healthy donors (p = 0.005) and in carcinoma lesions (p < 0.001). The highest CEA content was observed in benign lesions with severe dysplasia. No statistical correlation between CEA content in carcinoma tissues and serum CEA levels (r = 0.195, p = .13) was found. Therefore, in considering diagnosis or therapy with anti‐CEA MAbs for colorectal‐carcinoma patients, or potential therapies with anti‐CEA recombinant vaccines, serum CEA levels should not be taken as indicating CEA expression in tumor lesions. Int. J. Cancer 72:949–954, 1997.

Biomarkers of platelet activation in acute coronary syndromes

The most convincing evidence for the participation of platelets in arterial thrombosis in humans comes from studies of platelet activation in patients with acute coronary syndromes (ACS) and from trials of antiplatelet drugs. Both strongly support the concept that repeated episodes of platelet activation over the thrombogenic surface of a vulnerable plaque may contribute to the risk of death from coronary causes. However, the relation of in vivo platelet activation and adverse clinical events to results of platelet function tests remains largely unknown. A valuable marker of in vivo platelet activation should be specific, unaltered by pre-analytical artefacts and reproducibly measured by easily performed methods. This article describes current biomarkers of platelet activation in ACS, reviews their advantages and disadvantages, discusses their potential pitfalls, and demonstrates emerging data supporting the positive clinical implications of monitoring in vivo platelet activation in the setting of ACS.

Soluble P-selectin as a marker of in vivo platelet activation.

BACKGROUND Platelets are the major source of circulating sP-selectin. Elevated levels of this protein have been found in many atherothrombotic disorders. Thus, we investigated whether sP-selectin dosage might reflect platelet function in patients with risk factors for or with established cardiovascular diseases and whether its levels can be modulated by aspirin therapy. METHODS Plasma sP-selectin levels and light transmission platelet aggregometry (LTA) were analyzed in 152 outpatients. The effects of a 6-month aspirin therapeutic course on sP-selectin levels and LTA in 51 consecutive patients have been also investigated. RESULTS Significant correlations were observed between sP-selectin and Mx% LTA in response to epinephrine (p=0.022) and arachidonic acid (p=0.006), or between sP-selectin and collagen lag-phase (p=0.016). Multiple regression analysis showed that the only predictors of sP-selectin levels were platelet number (p<0.001) and collagen-induced lag-phase (p<0.01). Aspirin-treated patients showed a significant reduction of sP-selectin levels by 13% (p=0.021) which significantly correlated with collagen-induced lag-phase (p=0.005). CONCLUSIONS sP-selectin dosage could be proposed as a reliable marker of platelet activation in patients with major atherosclerotic risk factors either in the absence of clinically overt disease, and might represent a valid tool to asses in vivo platelet behavior.

Platelet function in health and disease: From molecular mechanisms, redox considerations to novel therapeutic opportunities

Increased oxidative stress appears to be of fundamental importance in the pathogenesis and development of several disease processes. Indeed, it is well known that reactive oxygen species (ROS) exert critical regulatory functions within the vascular wall, and it is, therefore, plausible that platelets represent a relevant target for their action. Platelet activation cascade (including receptor-mediated tethering to the endothelium, rolling, firm adhesion, aggregation, and thrombus formation) is tightly regulated. In addition to already well-defined platelet regulatory factors, ROS may participate in the regulation of platelet activation. It is already established that enhanced ROS release from the vascular wall can indirectly affect platelet activity by scavenging nitric oxide (NO), thereby decreasing the antiplatelet properties of endothelium. On the other hand, recent data suggest that platelets themselves generate ROS, which may evoke pro-thrombotic responses, triggering many biological processes participating in atherosclerosis initiation, progression, and complication. That oxidative stress may alter platelet function is conceivable when considering that antioxidants play a role in the prevention of cardiovascular disease, although the precise mechanism accounting for changes attributable to antioxidants in atherosclerosis remains unknown. It is possible that the effects of antioxidants may be a consequence of their enhancing or promoting the antiplatelet effects of NO derived from both endothelial cells and platelets. This review focuses on current knowledge regarding ROS-dependent regulation of platelet function in health and disease, and summarizes in vitro and in vivo evidence for their physiological and potential therapeutic relevance.

Vascular endothelial growth factor (VEGF-A) plasma levels in non-small cell lung cancer: Relationship with coagulation and platelet activation markers

Platelet activation, commonly found in lung cancer patients, may cause the release of angiogenic factors, such as vascular endothelial growth factor (VEGF-A). The present study was designed to investigate whether plasma VEGF-A levels were associated to different stages of non-small cell lung cancer (NSCLC). Moreover, sP-selectin, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complex (TATc) and D-dimer levels were measured to test the hypothesis of an involvement of platelet and coagulation activation in tumor angiogenesis. VEGF-A, sP-selectin, F1+2, TATc and D-dimer levels were elevated in 65 patients with NSCLC, particularly in metastatic patients. sP-selectin (p <0.003) and F1+2 (p <0.005) levels were independently associated to VEGF-A. In addition, patients with positive levels of both sP-selectin and F1+2 had the highest levels of VEGF-A. In conclusion, our findings support the hypothesis that thrombin generation might induce platelet activation and VEGF-A release in NSCLC.

TAG-72 (CA 72-4 assay) as a complementary serum tumor antigen to carcinoembryonic antigen in monitoring patients with colorectal cancer

Background. Serum carcinoembryonic antigen (CEA) is the most frequently chosen tumor marker in the clinical diagnosis of colorectal carcinoma and in the long‐term monitoring of patients after tumor resection. In recent years, monoclonal antibody technology has identified several new markers of neoplasia, two of which, TAG‐72 and CA 19‐9, are found in the sera of patients with adenocarcinoma. Serum CEA, TAG‐72, and CA 19‐9 were evaluated in 300 patients with either malignant (n = 200) or benign (n = 100) colorectal disease.

BRCA1 and BRCA2 mutations in central and southern Italian patients

Statement of findingsProtein truncation test (PTT) and single-strand conformation polymorphism (SSCP) assay were used to scan the BRCA1 and BRCA2 genes in 136 unrelated Italian breast/ovarian cancer patients. In the sample tested, BRCA1 and BRCA2 equally contributed to site-specific breast cancer patients who reported one to two breast cancer-affected first-/ second-degree relative(s) or who were diagnosed before age 40 years in the absence of a family history of breast/ovarian cancer. BRCA1 and BRCA2 mutations were mostly found in patients with disease diagnosis before and after age 50 years, respectively. Moreover, in cases with familial clustering of site-specific breast cancer, BRCA1 mostly accounted for tumours diagnosed before age 40 years and BRCA2 for tumours diagnosed after age 50 years. The BRCA1 and BRCA2 mutation spectrum was consistent with a lack of significant founder effects in the sample of patients studied.